Courtesy of Steven Engineering, Inc - (800) 258-9200 - [email protected] - www.stevenengineering.com For up-to-date product information, 2D/3D CAD drawings and detailed specifications, please visit www.bodine-electric.com About Us Bodine Electric Company offers over 1,200 standard products, and thousands of custom designed fractional horsepower (<746 Watts) gearmotors, motors and motion controls (fixed and variable speed AC, brushless DC, and permanent magnet DC). Bodine products are available via an extensive distributor network or sold directly to OEMs. Known for their reliability, long life and competitive prices, Bodine gearmotors and motors are designed for demanding industrial and commercial applications such as medical devices, scientific and laboratory equipment, labeling equipment, printing presses, packaging equipment, factory automation, and mobile and solar powered equipment. Bodine Electric is headquartered in Northfield, Illinois (20 miles north of Chicago) with manufacturing and assembly operations in Peosta, Iowa, U.S.A. Our quality management system is certified to ISO 9001:2008. MANAG Bodine Electric Company ITY GEE LLI M A EE UU NN 201 Northfield Road QQ TT D D SS EE I Y I Y F F Northfield, Illinois 60093 U.S.A. S S I I T T T T E E R R ISO M M E ISO E C www.bodine-electric.com C 9001:2008 [email protected] Phone: 773.478.3515 Copyright Notice: Small Gearmotors, Motors, and Controls Handbook ©2016 Bodine Electric Company. All rights reserved. Unauthorized duplication, distribution, or modification of this publication, in part or whole, is expressly prohibited. ISBN 9994675133. Library of Congress Catalog Number 92-076079. Courtesy of Steven Engineering, Inc - (800) 258-9200 - [email protected] - www.stevenengineering.com Contents Page 1 Electric Motor Fundamentals Basic Electricity . .1-1 Basic Magnetism . 1-6 Generators and Basic AC Circuits . .1-12 Basic Mechanical Principles . 1-20 2 AC Motors AC Motor Action . .2-1 Polyphase (Two or More Phases) Motors . 2-2 Single-Phase . .2-5 Single-Phase AC Motor Types . .2-5 Synchronous (Polyphase and Single-Phase) . 2-12 3 Commutator (DC) Motors Brush-Type DC Motor Action . .3-1 Brush-Type DC Motors . 3-3 Brushless DC Motor Action . .3-11 4 Special Purpose Motors Fractional Horsepower Gearmotors . .4-1 Low Speed AC Synchronous Motors . .4-2 Torque Motors . 4-3 Switched Reluctance Motors . .4-6 Linear Induction Motors . 4-7 DC and AC Servo Motors . 4-8 Shell-Type Armature Motor . .4-9 Printed Circuit (PC) Motor . 4-10 5 Basic Motor Construction Magnetic Materials and Motor Design . 5-1 Bearings . .5-6 Brushes . .5-9 Insulation Systems . .5-12 Environmental Protection . 5-13 6 Gearhead Construction Gearing . .6-1 Gear Trains . .6-4 Gearmotor Lubrication . .6-6 7 Motor/Gearmotor Selection and Application Motor and Gearmotor Industry Standards . .7-1 Motor and Gearmotor Nameplate Ratings . .7-3 Noise and Vibration . .7-10 Thermal Protection . .7-16 Energy Management . 7-19 Load Torque Measurement . 7-22 Motor Sizing . 7-24 Application Guidelines . 7-25 Safety . .7-40 Care and Servicing . .7-42 Courtesy of Steven Engineering, Inc - (800) 258-9200 - [email protected] - www.stevenengineering.com 8 Motor Controls Motion Control Systems . .8-2 Motor Operating Characteristics . .8-5 Motor Control Types . 8-12 Passive Device Motor Controls . 8-13 Solid State Electronic (Active) Motor Controls . .8-21 Solid State Electronic (Active) Control of AC Motors . 8-39 Motor Control Enclosure Standards . .8-42 9 Feedback Devices Tachometer Generators . 9-2 Encoders . .9-2 10 Clutches and Braking Techniques Electromechanical Clutches and Brakes . .10-1 Dynamic Braking . .10-7 Evaluation of Dynamic Braking Methods . 10-18 Appendix 1 List of Associations and Standards Organizations . A-1 2 Troubleshooting fhp Motors . .A-2 3 Helpful Shortcuts . .A-4 4 Motor Application Formulae . A-6 5 Properties of Materials . .A-8 6 Temperature Conversions . .A-9 7 SI (Metric) Conversion Table . A-10 8 Typical Gearmotor Construction . .A-11 9 Horsepower/Watts vs . Torque Conversion Chart . .A12 10 Specific Resistance of Metals and Alloys at Ordinary Temperatures . .A-17 11 NEMA Motor Frame Dimensions . A-18 12 International Voltage and Frequency Standards . A-19 Glossary . .G-1 Connection Diagrams . .CD-1 Index . .IN-1 Final Review . FR-1 Courtesy of Steven Engineering, Inc - (800) 258-9200 - [email protected] - www.stevenengineering.com Electric Motor Fundamentals Electric motors are designed to convert 1.1 BASIC electrical energy into mechanical energy to perform some physical task or work. In ELECTRICITY order to understand the types of motors that are available as well as their perfor- Electric Current (I) mance characteristics, some understanding Atomic theory describes matter as an of the basic physical principles governing aggregate of atoms. Each atom consists of motor design and operation are required. a nucleus containing positively charged Basic electric motor design encompass- protons and electrically neutral particles es the laws of electricity and magnetism. called neutrons. Revolving in orbits around Motor feedback and control systems in- the positive nucleus are negatively charged volve semiconductor devices, micropro- electrons. cessors and other elements of electronics. In metallic conductors (such as copper), And no discussion of motors would be one or more electrons from the outer orbits complete without a brief understanding of become detached from each atom and the mechanical principles governing linear move randomly from one atom to another. and angular motion. These are called free electrons. The posi- This Chapter of the Handbook pro- tive nucleus and the rest of the electrons vides an overview of these fundamentals so remain relatively fixed in position. Insula- that the reader will have a foundation on tors, on the other hand, contain virtually no which to build a better understanding of free electrons. motor design and performance specifica- When an electric field is applied to a tions. conductor, free electrons will drift under the influence of that electric field. Drifting electrons will collide with stationary atoms 1-1 Courtesy of Steven Engineering, Inc - (800) 258-9200 - [email protected] - www.stevenengineering.com causing additional free electrons to drift in between the two points results in a power the same direction. This movement of elec- dissipation of one watt. tric charge is called current. The unit of measurement for current or Resistance (R) rate of charge flow is the ampere. We Resistance is defined as the opposition speak of a direct current (DC) if the charg- to current flow. Although electrons may es always flow in the same direction, even flow in any substance, different materials though the amount of charge flow per unit offer different resistance to their flow. time may vary. If the flow of charge revers- Those which make the transfer of elec- es its direction periodically, then we have trons relatively easy are called conductors what is called alternating current (AC). A (copper, aluminum, steel, etc.), and those more detailed description of direct and which tend to impose substantial resistance alternating current is presented in Section are called insulators (wood, paper, mica, 1.3 of this Chapter. glass, etc.). Materials with a level of con- Conventional Current Flow: ductivity between these two extremes are Before the acceptance of the electron the- called semiconductors (germanium, sili- ory, it was assumed that the direction of con). These “inbetween” materials have current flow was from a positively charged become increasingly useful in the applica- body to a negatively charged body. This tion of electrical energy. positive to negative flow of current is called The unit of electrical resistance is the Ω conventional current flow. However, in a ohm ( ). One ohm is defined as the resis- metallic conductor, it is electrons that carry tance of a conductor which will allow a the charge from negative to positive. The current flow of one ampere when a poten- flow of current from negative to positive is tial difference of one volt is applied. The called electron flow. We will adopt con- resistance of a material is normally depen- ventional current flow throughout this dent on temperature. In general, the resis- Handbook. In the diagrams, the direction tance of metallic conductors increases with of current will always be from positive to temperature. negative. Ohm’s Law: Ohm’s law explains the relationship between voltage, current Potential Difference (V) and resistance. It states that the amount of Electrons will move between two points current through a conductor is directly pro- of a conductor if there is a potential differ- portional to voltage applied and inversely ence (or a difference of “electric pressure”) proportional to the resistance of the con- between the two points. Voltage is the ductor or circuit: measure of the amount of pressure needed V I = --- to push electrons through a conductor. It is R analogous to a water pump that maintains a pressure difference between its inlet and A conductor obeys Ohm’s law when, outlet and results in water flow. Potential for a given temperature, the current it con- difference and voltage are often used inter- ducts varies linearly with the applied volt- changeably. age (Fig. 1-1). The unit of potential difference or volt- Power: Electricity is used to perform age is the volt. A potential difference of some type of work or to generate heat. one volt will be dropped across two points Power is the rate at which work is done or if a constant current of one ampere flowing the rate at which heat is generated. The unit 1-2 Courtesy of Steven Engineering, Inc - (800) 258-9200 - [email protected] - www.stevenengineering.com Fig. 1-1: Current varies linearly with Fig. 1-2: Simplified series circuit. applied voltage in accordance with Ohm’s law. curremt flow.